Moisture-resistant cover floor system for concrete floors

ABSTRACT

A cover floor system for covering a sub floor is provided. The cover floor system has a plurality of interlocking floor tiles. The tiles have a cover floor surface and a grid of supporting legs adapted to elevate the cover floor surface over the sub floor and form a gap between the cover floor surface and the sub floor. At least two tiles are coupled together with a lap joint. The lap joint is formed by a first lap portion, disposed on one of the two tiles, and a mating second lap portion on the other tile. The first lap portion has a lower lap seating surface offset from the cover floor surface. The mating second lap portion has an upper lap surface seating against the lower lap seating surface and defining a substantially continuous lap scene along interfacing sides of the two tiles when the tiles are coupled.

RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No. 10/624,290 Filed Jul. 21, 2003 hereby incorporated by reference in its entirety.

BACKGROUND

1. Field of the Embodiments

The disclosed embodiments relate to a cover floor system for covering sub floors and, such as a moisture resistant sub floor tile system for covering concrete floors.

2. Description of Earlier Related Developments

Concrete floors, particularly concrete floors installed or poured over the dirt surfaces of sub-terranean rooms such as basement living spaces of homes or the ground-level rooms or work spaces of slab-homes or buildings, are particularly susceptible to water vapor penetration. Such concrete floors may be covered with plastic tiles or carpeting to improve their appearance and make them more comfortable to the feel. However, concrete floors are relatively porous and also conduct the cold temperature of the ground, which can result in water vapor penetration and condensation at the interior surface of the concrete floor, causing separation of plastic floor tiles adhered thereto or causing a moisture accumulation in carpeting adhered thereto or applied there over, resulting in mold or mildew. Water vapor and water can penetrate and diffuse through the porous concrete floor from the dampness of the soil or ground beneath the concrete, and also through cracks which can develop in the concrete and/or also can penetrate through interfaces between the floor and the walls and/or footings. As a result, sub-floors may be built over concrete floors using wooden studs as spacers and covering them with plywood to form an interior floor surface which is then covered by floor tile or carpeting. Such a system is an insulation improvement, but takes up to 2″ of headroom or more. Water vapor can be absorbed by the wooden studs and plywood, resulting in mold, mildew, rot and odors, and separation of tiles from the plywood floor. An alternative to the finished surface being directly applied to the concrete or to a wood based sub floor system with the finished surface being applied to it as described is to provide a modular floor tile system where the finished surface is made up of a series of interlocking plastic tiles that are seated on the concrete. Such a system is disclosed in U.S. Pat. No. 6,098,354. A problem with such a modular tile system arises where water vapor from the concrete floor may still penetrate into the room through the joints between the tiles. A further problem arises in such a system where temperature changes cause thermal expansion and contraction of the tiles. Here, with a rigid interlocking system, the tiles are over constrained potentially causing buckling, joint failure or gaps at the peripheral edges. Accordingly, there is a desire to provide a sub floor system upon which a finished surface may be applied that is not over constrained and that prevents the migration of water vapor from the concrete floor to the covering or the room.

SUMMARY OF THE EMBODIMENTS

In accordance with the first exemplary embodiment a cover floor system for covering a sub floor is provided. The cover floor system comprises a plurality of interlocking floor tiles. The tiles have a cover floor surface and a grid of supporting legs adapted to elevate the cover floor surface over the sub floor and form a gap between the cover floor surface and the sub floor. At least two tiles are coupled together with a lap joint. The lap joint is formed by a first lap portion, disposed on one of the two tiles, and a mating second lap portion on the other tile. The first lap portion has a lower lap seating surface offset from the cover floor surface. The mating second lap portion has an upper lap surface seating against the lower lap seating surface and defining a substantially continuous lap scene along interfacing sides of the two tiles when the tiles are coupled.

In accordance with another exemplary embodiment a cover floor system is provided. The floor system comprises a plurality of interlocking floor tiles. The tiles have a cover floor surface and a grid of supporting legs adapted to elevate the cover floor surface over the sub floor and form a gap between the cover floor surface and sub floor. The interlocking tiles are coupled together with lap joints capable of sealing interfacing edges of adjoining tiles against infiltration of water vapor and moisture between the interfacing edges. At least one of the interlocking tiles is anchored to the sub floor anchoring the cover floor surface of the floor system.

In accordance with another exemplary embodiment a floor covering for covering a basement concrete floor is provided. The floor covering comprises a super floor and a carpet or other floor covering. The super floor is adapted to be superposed over and supporting by the concrete floor. The carpet or other floor covering is supported by the super floor. The super floor has a plurality of interlocking floor tiles. The floor tiles have a cover floor surface upon which the carpet or other floor covering is disposed. The tiles are coupled together with a floating interlocking joint providing relative play between the interlocking floor tiles allowing the interlocking floor tiles to move relative to each other. The floating interlocking joint substantially prevents water vapor and moisture from passing from the concrete floor through the cover floor surface to the carpet or other floor covering.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other features of the exemplary embodiments are explained in the following description, taken in connection with the accompanying drawings, wherein:

FIG. 1 is an isometric view of a basement corner and a floor system, incorporating features in accordance with an exemplary embodiment, disposed on the basement floor;

FIG. 2 is an isometric view of the upper surface of a floor tile of the floor system in FIG. 1;

FIG. 3 is an isometric view of the lower surface of the floor tile in FIG. 2;

FIG. 4 is a plan view of the upper surface of the floor tile;

FIG. 5 is a plan view of the lower surface of the floor tile;

FIG. 6 is an isometric view of a corner of the upper surface of the floor tile;

FIG. 7 is an isometric view of a corner of the lower surface of the floor tile;

FIG. 8 is an end view of the floor tile as seen along view lines 8-8 in FIG. 4;

FIG. 9 is another end view of the floor tile as seen along view lines 9-9 in FIG. 4;

FIG. 10 is a section view of the floor tile taken along lines 10-10 in FIG. 5;

FIG. 11 is a section view of the floor tile taken along lines 11-11 in FIG. 5; and

FIG. 12 is a partial section view of a floating joint between tiles of the floor system.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT(S)

Referring to FIG. 1, there is shown an isometric view of a basement corner having a floor and a cover or upper floor system 20 incorporating features in accordance with an exemplary embodiment. Although the present invention will be described with reference to the embodiments shown in the drawings, it should be understood that the present invention can be embodied in many alternate forms of embodiments. In addition, any suitable size, shape or type of elements or materials could be used.

In the embodiment shown, a system 20 is provided for flooring, through the floor surfaces of the flooring system, of over for example, on-grade concrete floors and preventing water vapor and moisture penetration through the floor surfaces of the flooring system, of and for insulating them from the temperatures of the surrounding soil. System 20 generally involves interposing an insulating, thermal air-gap forming, cover floor 24, for example made of high density plastic that acts as a barrier between concrete floor 26 and carpet or other suitable floor covering 28. Cover floor 24 may generally cover the concrete floor 26 of a basement, or at least a desired portion thereof and provides a floor surface 24S for supporting carpet or other floor covering 28. Although the flooring system 20 of the exemplary embodiment will be described below with specific reference to application onto a basement floor, in alternate embodiments the flooring system may be used with, and the features of the exemplary embodiment are equally applicable to installation on any desired type of sub floor. In FIG. 1, the floor covering system 20 is shown assembled to cover at least a portion of the basement floor 26. For purposes of the description the basement floor 26 will be referred to as a sub floor in regards to the cover floor surface 26S formed by the cover floor of the system 20. Flooring system 20 may generally be similar to the floor cover system described in U.S. patent application Ser. No. 10/624,290, filed Jul. 21, 2003 previously incorporated by reference herein in its entirety.

In the exemplary embodiment, cover floor 24 is shown fastened, for example at least at one location to the concrete floor, preventing the cover floor from moving or shifting as a unit over the sub floor, but does not over constrain the cover floor and can accommodate relative movement between cover floor and sub floor. For example, are to thermal expansion/contraction, as will be described in greater detail further below. In alternate embodiments, cover floor may not be fastened at all to concrete floor. Free play may be built into the interlocking floor tiles to allow for expansion and contraction. Cover floor 24 may comprise an interlocking floor tiles 32, 34 and acts as a barrier to prevent passage of water or water vapor from below the cover floor 24, for example, due to plumbing, water heater leaks or flooding. The tiles that make up cover floor 24 may be made from a suitable material, such as plastic, (e.g. molded polypropylene or polyethylene). The plastic material for example, may use no organic materials. As may be realized, a plastic cover floor 24 will not delaminate in a moist atmosphere and will not support mold and the consequences thereof. Cover floor 24 has a solid, planar or flat upper surface 24S, that may be substantially impermeable to moisture and water vapor and may support carpet 28 or padding 30 as an outer covering, if desired. In alternate embodiments, the cover floor surface may not be covered and may act as the primary floor surface. In alternate embodiments, any suitable floor covering may be used in combination with the cover floor. The cover floor surface 24S may be elevated over the basement sub floor and isolated from the concrete floor by a barrier air gap described below.

Water vapor can not penetrate the plastic barrier cover floor 24 from the porous concrete either through the tiles, for example, tiles 32, 34 or through the inter tile joints, for example, joints 36, 38 between the plastic tiles. In this exemplary embodiment, interlocking floor tiles 32, 34 are coupled together with a lap joint 36, 38. The lap joint 36, 38 may be formed by a first lap portion on tile 34 and a mating second lap portion on tile 32. As will be described in greater detail below, the first lap portion has a lower lap or seating surface, in the exemplary embodiment, substantially parallel to, and offset from the floor surface 24S. The mating second lap portion has an upper lap surface positioned to seat against the seating surface of the first lap portion. In the exemplary embodiment, the upper lap surface may be parallel to, and offset from the floor surface 24S. In the exemplary embodiment, the interlocking joint(s) 36,38 coupling the floor tiles 32, 34 together and having in the exemplary embodiment a, lap fit, formed by the first portion and the mating second portion, may also be configured (as will be described further below) to provide relative play between the interlocking floor tiles allowing the interlocking floor tiles to thermally expand and contract. Hence, the lap fit at the interlocking joints may be referred to as a variable or floating lap and the joints, for example joint(s) 36, 38 as floating lap joints. In the embodiment shown, the floor cover surface 24S in cooperation with the lap joint(s) 36, 38 may substantially prevent water vapor and moisture from passing from the concrete floor to an interior space of the basement. As a result, a water-resistant flooring system is provided for insulating against dampness and cold penetration from concrete sub-floors, and which will not be damaged by water penetration from any direction or source, including above-floor plumbing problems or flooding.

In greater detail now, and referring still to FIG. 1 in the embodiment shown, the tiles that make up cover floor 24 may be substantially similar to each other. In alternate embodiments, the cover floor tiles may be different in size and shape. In the exemplary embodiment, the tiles 32, 34 may have any desired size and shape such as 6″, 12″, 17″, 24″ square or 48″ or even 4×8 rectangular sheets, and for example, about ⅜″ to ¾″ thick, which fit or interlock together such as with a floating lap joint, as will be described in more detail below. In alternate embodiments, the tiles may have any desired size and shape. The tiles, for example tiles 32, 34, that make up a flooring system, may comprise a strong, substantially rigid, and substantially flat, solid layer or panel of water-resistant or impervious plastic, such as ABS, polyvinyl chloride, polyethylene, polypropylene or polycarbonate, which is either molded with integral spaced plastic legs or spacers such as studs or slots, or other raised areas on the underside thereof. In alternate embodiments, the solid panel of the tile may be laminated, bonded, or otherwise attached to a separate water-resistant solid plastic barrier sheet which is molded with integral spaced plastic legs or spacers such as studs, slots or other raised and/or depressed areas on the underside thereof. The spaced leg portions may contact the surface of the concrete floor and thus space and support the underside of the flat plastic panel from the surface of the concrete floor to provide an insulating thermal air gap barrier space. The barrier space or gap provided thereby may be of any suitable size, for example between about ⅛″ and 1″ high, to admit and circulate any water vapor, for example, penetrating up through or collecting on the concrete floor beneath the cover floor layer 24. In the exemplary embodiment, the air gap barrier space may provide a space network within which the water vapor may circulate and come into equilibrium with the water content of the porous concrete floor. As a result, water condensation may be avoided or substantially reduced by the spacers or leg portions which create the air gap barrier space. Water vapor from the concrete floor cannot condense within the air gap, and humid air from the basement living space cannot penetrate the interlocked plastic tiles to condense on the concrete floor. In alternate embodiments the barrier gap between cover floor and sub floor may be vented, by passive or active means, and exhausted for example outside the basement or other suitable space. The top surfaces of the plastic panel may be planar and may have a desired surface characteristic such as a decorative design formed thereon, or the planar upper surface of the plastic barrier tile layer may have a color which is aesthetic, or the tile layer may be after-covered with a conventional ceramic or plastic tile layer or with carpeting or a vinyl surface such as linoleum or vinyl flooring.

Referring now to FIG. 2, there is shown an isometric view of the upper surface 40 of floor tile 32. Referring also to FIG. 3, there is shown an isometric view of the lower surface 44 of floor tile 32. Referring also to FIG. 4, there is shown a plan view of the upper surface 40 of floor tile 32. Referring also to FIG. 5, there is shown a plan view of the lower surface 44 of floor tile 32. In the embodiment shown, plastic tile 32 is molded as a unitary plastic tile element. In alternate embodiments, plastic tile 32 can be formed with planar upper and lower surfaces with a number of individual plastic studs or spacers and network walls, adhered to the planar lower tile surface. In alternate embodiments, any suitable method may be applied in fabricating tile 32. As noted before, plastic tile board 32 may be in the form of a 12 inch square tile board having opposed edges designed to form a lap joint. In alternate embodiments any suitable size or shape may be provided. Tile 32 has a first mating portion 50, 52 along two edges and a second mating portion 54, 56 along the other two edges (see FIGS. 2-3). The first mating portion is provided for mating with corresponding complementary second mating portions on adjacent tiles to lock the tiles to each other and produce a substantially-continuous, smooth floor surface which is substantially water impervious. The configuration of the first and second mating portions shown in FIGS. 2-5 is merely exemplary, and the tile mating portions may have any other suitable configuration in alternate embodiments. As seen in FIGS. 2-4, in the exemplary embodiment where each interlocking floor tile may have four sides two of the four sides comprise the first portion, and the other two of the four sides comprise the mating second portion. In the exemplary embodiment, interlocking floor tile 32 comprises a number of pins 80 and a matching number of hoops 82 (in alternate embodiments more or fewer pins and hoops may be provided).

As seen in FIG. 1, the cover floor 24 is formed from multiple tiles, each provided with complimentary mating first and second portions, the tiles may be interlocked in any manner where the hoops and the pins align. For example, two tiles 32, 32A may be connected in line with each other or tiles 32, 34 may be offset one from another as shown in FIG. 1 for example the amount of lateral offset between tile edges may a multiple of the pitch 84 shared by the pins and the hoops. As noted before, in the exemplary embodiment, the interlocking floor tiles are coupled together with a lap joint formed by the first mating portion and a mating second portion of the tiles. As seen in FIG. 2, first portion 50, 52 has a lower lap surface 86 (see also FIG. 6). In the exemplary embodiment the lower lap surface, that forms a lap seat for the second mating portion, may be substantially parallel to and offset from the floor covering supporting surface. In alternate embodiments, the lower lap surface may have any desired configuration. In the exemplary embodiment, the lower lap surface has a hoop(s) 82 formed therein. The lower lap surface forms a substantially continuous surface along corresponding edges of the tile. The mating second portion 54, 56 has an upper lap surface 88 generally disposed to complement the lower lap surface 86. Hence, in the exemplary embodiment, the upper lap surface may be parallel to and offset from the floor cover surface 40, though in alternate embodiments the upper lap surface may have any desired shape. In the embodiment shown, upper lap surface 88 is shown having molded recesses 90 (see also FIG. 7). In alternate embodiments, molded recesses 90 may not be provided. In the embodiment shown, the lower lap surface of a tile 32 mates with the upper lap surface of a corresponding mating tile 34. In the exemplary embodiment the lower lapped surface may be movable relative to the mating upper lap surface of the corresponding tile as will be described below. As generally described before and seen best in FIG. 3, each tile 32, 34 has a solid planar upper surface 40 and a discontinuous under surface comprising spaced support studs or legs and wall sections which project a distance from the undersurface of the tile to contact the supporting surface, of the sub floor such as the concrete basement floor. In the exemplary embodiment shown in FIG. 3, the undersurface comprises spaced intermediate network wall sections which project a lesser distance from the undersurface of the tile and do not contact the surface of the supporting floor. As discussed before the resulting space network operates to inhibit condensation on the surfaces of the barrier space between the underside and sub floor. The network sections shown in FIG. 3 is merely exemplary, generally comprising a wall grid work, to form substantially square compartments, with diagonal, intermediate height, bracing walls and a central post or support leg of maximum height. In order to provide a circulation airspace beneath the tile 32 openings or ports are provided in the perimeter walls to enable any water vapor to circulate or be moved through an air circulation network beneath all areas of each tile and across the joint of mating tiles. Air circulation spaces are provided between adjacent tiles between the lap joints along adjacent edges of each tile. In the exemplary embodiment shown, floor tile 32 has a floor covering surface 40 and an array of supporting legs 58, 60, 62 adapted to allow water vapor and moisture to pass between the floor covering surface 40 and the concrete floor. Plastic tile 32 are molded to have integral spaced plastic support studs or legs 58, 60 or wall sections 62 projecting a maximum distance from the underside 64 of supporting surface 40 to form lower tile surface 44 that contacts the concrete sub floor. Legs or studs 58, 60 and wall sections 62 are repeated and shown for example in staggered and offset rows such that the tile is uniformly supported. These sections may have any desired height such as ⅛″ up to about 1″, for example about ⅜″, and may be closely spaced and staggered in rows, as shown, for desired tile support and stability. Intermediate plastic grid sections 66, 68, 70, 72 of intermediate height are also provided, allowing air and vapor to freely pass between the bottom of the sections 66-72 and sub floor when the tile is seated with the full height leg or wall sections against the sub floor. Intermediate sections also provide structural integrity to tile 32 in order to effectively support desired loads. (See also FIGS. 8-9, that show respective end views of the representative tile 32, and FIGS. 10-11 showing different sections/views illustrating the sections of tile 32 and passages and network array formed thereby.) In the exemplary embodiment, intermediate wall sections may also define the airspace network that is continuous and open, and serves as thermal break and accumulator of water vapor under the tile cover floor surface. In the exemplary embodiment, grid sections 68-72 may further define the array of insulation spaces or chamber provided on the underside of the tile board and over the interconnect air space network separating the tile surface 40 and basement floor. In the embodiment shown, studs or legs 58, 60 or wall sections 62 may be spaced from each other to provide a desired distribution of the interconnected airspace network, under each tile, and hence under the cover floor 24 (see FIG. 1) to prevent water vapor passing between concrete floor and cover floor from being isolated in any chambers created by the tile legs or standoffs, so that the water vapor does not condense into water under tile 32. As noted before, the interconnected airspace under the cover floor 24 allows drying of any water that may temporarily collect under the floor tiles, (e.g. water from an above-floor plumbing leak, water heater leak, etc. or water from a periodic groundwater leak such as from the floor-wall joint of the foundation). As also noted before, a vent (not shown) may be provided to vent the space between the concrete floor surface and the underside of the tiles. For example, this can be done passively, such as at the edge of the floor, or actively, such as with a fan, to blow air under or to draw air from under the floor and exhaust it into a desired space (e.g. an interior collector) or outside of the building, to dry the space under the floor either continuously or only when desired.

Referring now to FIG. 6, there is shown an isometric view of a corner of the upper (i.e. floor) surface 40 of floor tile 32. Referring also to FIG. 7, there is shown an isometric view of a corner of the lower surface 44 of exemplary floor tile 32. As noted previously, lower lap surface 86 that forms the lower seating surface of the coupling lap joints, may be in the exemplary embodiment, generally, parallel to surface 40 and offset from the cover floor complement lap surface (formed by surface 40) by an amount 92 (see FIG. 6). Distance amount 92 may be about equal to thickness 94 of portion 54, that in the exemplary embodiment may extend from surface 40 making up upper lap surface 88. In alternate embodiments, the lapping portions of tiles may have any other desired shapes forming a lap fit joint when the tiles are mated. As seen best in FIG. 6, in the exemplary embodiment the lower lap surface has hoops 82 formed therein. Hoops 82 have a radius portion 98 and a notched portion 100 (see FIG. 7). A retaining surface 102 may be provided to engage with a retaining tab of a tile mated to tile 32. As seen in FIGS. 6-7, in the exemplary embodiment, the lower lap surface 86 forms a substantially continuous surface penetrated by hoops 82. In alternate embodiments, the hoops may be separate and independent from the lower lap surface. In other alternate embodiments, the lower lap surface may have mating pins, similar to pins 80, formed thereon. Complementing lap portion 54 has upper lap surface 88 positioned to seat in a complementary manner on the lower lap surface 86 (of a mating tile). In the exemplary embodiment, the upper lap surface may be generally parallel to and offset from the floor covering supporting surface 40. In the embodiment shown, upper lap surface 88 is shown having molded recesses 90. This may provide increased seating pressure between lap surfaces. In alternate embodiments, molded recesses 90 may not be provided. As seen best in FIG. 7, pin 80 and resiliently flexible retaining tab 104 are provided coupled to upper lap surface 88. In the exemplary embodiment pin 80, tab 104 shown, form in effect a cross sectionally resiliently variable coupling pin. In the exemplary embodiment, pin 80 may have a general a c-shaped cross section. In alternate embodiments, any suitable shape may be provided. The shape of the pin 80 may allow relative movement in the loop 82 (as indicated by arrow A in FIG. 7). Retaining tab 104 is provided to bias and engage a retaining surface of a tile mated to tile 32 to provide a firm but pliant coupling between tiles. In the embodiment shown, the lower lap surface mates with the upper lap surface of a corresponding tile and is movable relative to the upper lap surface of the corresponding tile.

Referring now to FIG. 12, there is shown a section view of an exemplary resiliently floating lap joint 50 between floor tile 32 and floor tile 34. The interlocking floor tiles 32, 34 are coupled together with a lap joint similar to lap joint 36 having a first lap portion and a mating second lap portion. As seen in FIG. 12, the lap joint 50 provides relative play between the interlocking floor tiles allowing the interlocking floor tiles to move relative to each other, for example due to thermally expansion and contraction. Lower lap surface 86′ is provided parallel to surface 42 and offset from the cover floor surface 42 by an amount 92 about equal to thickness 94 of portion 54 extending from surface 40 making up upper lap surface 88. The lower lap surface 86′ has hoop 82′ formed therein. Hoops 82′ have a radius portion 98′ and a notched portion 100′. A retaining surface 102′ may be provided to engage with resiliently flexible retaining tab 104 of tile 32 mated to Tile 34. Retaining tab 104 may have lead a lead in portion 116, that may be tapered or ramped, allowing the extension portion 118 of tab 104 to resiliently deflect during assembly (in the direction indicated by arrow R in FIG. 12) to the point where tab 104 clears retaining portion 102′, snapping in position. Engagement portion 120 interfaces with retaining portion 102′ and may be tapered to allow nominal clearance or to preload the lap joint together as shown in FIG. 12. Engagement portion 120 has length 122 that is greater than desired resilient flexure 114, such that engagement portion 120 does not disengage the retaining portion 102′ during expansion and contraction of the tiles or from other movement. Here, the lower lap surface 86′ forms a substantially continuous surface surrounding hoops 82′. As seen in FIG. 12, lap portion 54 has upper lap surface 88 seated against lower lap surface 86. Pin 80 may be tapered, for example at section 124, enabling ease of assembly. In the exemplary embodiment, retaining tab 104 engagement of retaining surface 102′ prevents the interlocking floor tiles from separating in direction 112 and creating discontinuities in the floor covering supporting surface. In the embodiment shown, the lower lap surface 86′ mates with the upper lap surface 88 of tile 32 and is movable in direction 108 relative to the upper lap surface of the corresponding tile. The relative play is enabled with clearance 114 provided between pin 80 and hoop 82′. That is capable of accommodating relative movement in the direction indicated by arrow A in FIG. 7 (out of plane of the figures in FIG. 12) Clearance 114 allows pin 80 to move in direction 108 relative to hoop 82′. In the embodiment shown, the joint may be provided with additional sealant 110, for example, such as silicone or a gasket to further enhance the isolation between the concrete to the flooring.

Referring now again to FIG. 1, as noted before, in the exemplary embodiment one or more tiles 32 may be anchored (via fasteners, adhesive, etc.) to the basement sub floor 26. Relative movement between coupled tiles (anchored and unanchored), due to thermal expansion/contraction, may be accommodated in the exemplary embodiment by the movable lap joints. Anchorment of the cover floor tiles facilitates an improved installation and fit or any surface floor covering 28, 30 (e.g. carpeting, vinyl flooring, etc.) preventing shifting, distortion and/or potential lifting of the surface covering that may result from the movement of the cover floor 24S as a unit.

It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims. 

1. A cover floor system for covering a floor, the system comprising: a plurality of interlocking floor tiles, the tiles having a cover floor surface and a grid of supporting legs adapted to elevate the cover floor surface over the floor and form a gap between the cover floor surface and floor; at least two of the tiles being coupled together with a lap joint formed by a first lap portion, disposed on one of the at least two tiles, and a mating second lap portion disposed on another of the at least two tiles; the first lap portion having a lower lap seating surface offset from the cover floor surface, and the mating second lap portion having an upper lap surface seating against the lower lap seating surface and defining a substantially continuous lap seam along interfacing sides of the at least two tiles when the at least two tiles are coupled together.
 2. The system of claim 1, wherein the cover floor surface extends over the lap seam.
 3. The system of claim 1, wherein the lower lap seating surface has a hoop formed therein, and the upper lap surface has a pin projecting therefrom and wherein, when the lower lap seating surface and the upper lap surface are mated one to the other, the pin is engaged through the hoop.
 4. The system of claim 1, wherein the cover floor surface and the lap joint substantially prevent water vapor and moisture from passing through the floor cover floor surface, formed by the interlocking tiles, to a space above the cover floor surface.
 5. The system of claim 1, wherein the floor is a basement concrete floor, and the gap between cover floor surface and basement floor is arranged to allow water vapor and gasses to pass between the cover floor surface and the concrete floor.
 6. The system of claim 1, wherein the first lap portion comprises a retaining surface, and wherein, the mating second lap portion comprises a retaining tab, and wherein the retaining tab engages the retaining surface preventing lifting of the cover floor surface between the at least two interlocking tiles.
 7. The system of claim 1, wherein at least one of the interlocking tiles is anchored to the floor anchoring the system to the floor, and at least another of the interlocking tiles unanchored to the floor and is capable of movement relative to the floor.
 8. The system of claim 1, wherein free play is built into interlocking joints of the interlocking tiles allowing for relative movement between interlocking tiles and floor.
 9. The system of claim 1, wherein the pin extends to the floor and supports the floor covering supporting surface.
 10. The system of claim 1, wherein the interlocking floor tiles comprise molded polypropylene.
 11. The system of claim 1, wherein each of the interlocking tiles is a substantial square tile having four sides, and wherein two of the four sides comprise have the first lap portion disposed thereon, and wherein another two of the four sides have the mating second lap portion disposed thereon.
 12. A cover floor system for covering a floor, the system comprising: a plurality of interlocking floor tiles, the tiles having a cover floor surface and a grid of supporting legs adapted to elevate the cover floor surface over the floor and form a gap between the cover floor surface and floor; the interlocking floor tiles coupled together with lap joints capable of sealing interfacing edges of adjoining tiles against infiltration of water vapor and moisture between the interfacing edges; wherein at least one of the interlocking tiles is anchored to the floor anchoring the cover floor surface defined by interlocked tiles to the floor.
 13. The system of claim 12, wherein the lap joints provides relative play between the interlocking tiles allowing unanchored interlocking floor tiles to move relative to the floor.
 14. The system of claim 12, further comprising a surface layer superposed over the cover floor surface of the interlocking tiles.
 15. The system of claim 14, wherein the superposed layer is a carpeting or vinyl layer.
 16. The system of claim 12, wherein each interlocking floor tile comprises a plurality of pins and a plurality of hoops for interlocking the tiles.
 17. The system of claim 12, wherein the interlocking floor tiles are made of molded polypropylene.
 18. A floor covering for covering a basement concrete floor, the floor covering comprising: a super floor adapted to be superposed over and supported by the concrete floor; a carpet or other floor covering supported by the super floor; the super floor having a plurality of interlocking floor tiles, the floor tiles having a cover floor surface, upon which the carpet or other floor covering is disposed; the interlocking floor tiles coupled together with a floating interlocking joint providing relative play between the interlocking floor tiles allowing the interlocking floor tiles to move relative to each other; wherein, the floating interlocking joint substantially prevents water vapor and moisture from passing from the concrete floor through the cover floor surface to the carpet or other floor covering.
 19. The floor covering of claim 18, wherein the floating interlocking joint is a floating lap joint, and is adapted to accommodate relative movement between interlocking floor tiles due to thermal expansion or contraction of the tiles.
 20. The floor covering of claim 18, wherein at least one of the interlocking floor tiles is fastened to the concrete floor, and wherein, the interlocking floor tiles have a grid of supporting legs adapted to allow water vapor and moisture to pass between the cover floor surface and the concrete floor. 